Willner-Pardo (Daphne Eloise Slater, Who's Tall for Her Age) displays a dry wit and a finely tuned ear for dialogue in this breezy tale of best friends and bravery. Every summer, nine-year-old Sophie and her pal Annalise spend their vacation hanging out at the community pool, where usually ""the only things you have to worry about are Mario Esposito giving you a wedgie and the vending machine running out of grape soda."" This year, however, things take a nose-dive when Maggie and Jennifer (the ""coolest girls in our class"") invite them to jump off the high dive. Too scared to join in--and dismayed at being called ""chicken""--Sophie comes up with a plan to boost her bravura. As she works her way through a list of five tests of courage (from sleeping without her night-light to eating some bugs), her friendship with Annalise is also tested. In the end (thanks to some help from Dad), she conquers the high dive and the friendship survives intact. The author peppers Sophie's first-person narrative with wry observations (at the beginning of summer, she notes that ""the moms looked red and blotchy and embarrassed for everyone to be seeing their legs"") and spins a credible story about a situation every middle-grader will recognize. Final artwork not seen by PW. Ages 8-11. (Apr.)